| (a) | Spermatogonia produce sperm cells by spermatogenesis that begins at puberty. |
| (b) | All spermatogonia periodically undergo meiosis. |
| (c) | A primary spermatocyte completes first meiotic division during embryonic development. |
| (d) | The secondary spermatocytes have only 23 chromosomes each. |
| Assertion (A): | During pregnancy, the level of several hormones like estrogens, progestogens, cortisol, prolactin, thyroxine, etc are increased several folds in the maternal blood. |
| Reason (R): | Increased production of these hormones is essential for supporting the foetal growth, metabolic changes in the mother, and maintenance of pregnancy. |
| 1. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 2. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
| (i) | Relaxin is secreted by the ovary in the later phase of pregnancy. |
| (ii) | Inner cell mass differentiates into ectoderm and endoderm just before implantation. |
| (iii) | Implantation leads to pregnancy. |
| (iv) | Embryo with 8 to 16 blastomeres is called morula. |
| 1. | menstrual phase of the menstrual cycle |
| 2. | follicular phase of the menstrual cycle |
| 3. | ovulatory phase of the menstrual cycle |
| 4. | luteal phase of the menstrual cycle |
| 1. | The seminiferous tubules of the testis open into the vasa efferentia through the rete testis. |
| 2. | The vasa efferentia leave the testis and open into the epididymis located along the posterior surface of each testis. |
| 3. | The epididymis leads to the vas deferens that ascend to the abdomen and loop over the urinary bladder. |
| 4. | The epididymis receives a duct from the seminal vesicle and opens into the urethra as the ejaculatory duct. |
| 1. | the vas deferens with the duct of the bulbourethral gland |
| 2. | the vas deferens with the duct of the seminal vesicle |
| 3. | the epididymis and the vas deferens |
| 4. | the duct of bulbourethral gland and the urethra |